Brain Magnetic Resonance Imaging Abnormalities in Eosinophilic Meningitis Caused by Angiostrongylus cantonensis Infection

Angiostrongylus cantonensis is a parasite endemic in the Southeast Asian and Pacific regions. Humans are incidentally infected either by eating uncooked intermediate hosts or by consuming vegetables containing the living third-stage larvae. Reports on brain magnetic resonance imaging (MRI) findings and how they correlate with clinical features are limited in the literature. In this retrospective study, we investigated the brain MR features of eosinophilic meningitis caused by human infection with A. cantonensis. A detailed clinical study of 26 of these patients was conducted. The brain MRI findings were nonspecific, ranging from normal (n=1), leptomeningeal enhancement (n=21), hyperintense signal lesions (n=11) on T2-weighted MRI and nodular enhancing lesions in gadolinium-enhanced T1W1 (n=1). There was an association between the presence of brain MRI high signal intensities with peripheral eosinophilia (p=0.02), cerebrospinal fluid (CSF), eosinophil count >= 10%, and the presence of CSF antibodies to A. cantonensis (p =0.01). The patients with leptomeningeal enhancement in brain MRI tended to be younger and predominantly men (p=0.03). The time from onset of symptom to spinal tapping or brain MRI studies did not have an effect on the presence of brain MRI abnormalities. The brain MRI findings did not add any additional importance to the clinical evaluation of patients with eosinophilic meningitis in this series. Further studies are required to clarify the role of brain MRI in eosinophilic meningitis.